Grinding machine

ABSTRACT

A grinding machine enabling the easy maintenance and inspections of mechanisms arranged therein, an increase in visibility when the states of a workpiece and a grinding wheel are confirmed, and the easy loading/unloading of the workpiece and the easy replacement of the grinding wheel. The grinding machine comprises a workpiece supporting/driving device, a wheel work head, a wheel head feeder, a coolant supply unit, a cover covering internal devices such as the workpiece supporting/driving device, the wheel work head, the wheel head feeder, and the coolant supply unit, and an open/close door formed at a part of the working space side upper surface of the cover and allowing at least the loading/unloading of the workpiece and the replacement of the grinding wheel.

TECHNICAL FIELD

This invention relates to a grinding machine to grind a workpiece byusing a rotating grinding wheel and, in particular, to a grindingmachine that allows easy maintenance and inspection of mechanismsarranged therein, enhancement in visibility required when confirming thestate of a workpiece and a grinding wheel, easy loading/unloading of theworkpiece, and easy replacement of the grinding wheel.

BACKGROUND ART

Conventionally, a grinding machine is known in which a grinding wheelhead supporting a grinding wheel to be rotatably driven is mounted overa bed through a sliding mechanism to be movable toward a work head and afoot stock, and which is operable to grind, by using the grinding wheel,a workpiece supported between the work head and the foot stock to berotatably driven while supplying a coolant over the workpiece from acoolant nozzle (e.g., Patent Literatures 1 and 2). Some of the grindingmachines have a cover for preventing dispersal of a coolant, a grindingdust etc. and for protecting the machine from external dust etc.

Patent Literature 1 discloses a grinding machine that has a whole coverwhich covers the whole of the work head, the foot stock, the grindingwheel head and the sliding mechanism of the grinding wheel head, asliding door is formed in the middle portion of the front face of thebed to open/close in loading/unloading of the workpiece, and doubledoors are formed on both sides of the whole cover to allow themaintenance and inspection of devices such as the sliding mechanism ofthe grinding wheel head.

Patent Literature 2 discloses a grinding machine that allows thereplacement of a workpiece through a workpiece loading/unloading port byusing a workpiece loading/unloading device when a protective cover isopen.

Patent Literature 1: JP-2003-117828 (page 4—right column, page 5—rightcolumn to page 6—left column, FIG. 1, and FIG. 7)

Patent Literature 2: JP-2002-103216 (page 3—left column, FIG. 1, andFIG. 2)

DISCLOSURE OF INVENTION Problems To Be Solved By The Invention

However, the conventional grinding machine in Patent Literatures 1 and 2has problems that ergonomic data are not considered in design regardingto workability in loading/unloading a workpiece, in replacing a grindingwheel or in maintaining and inspecting mechanisms arranged therein, orto visibility in confirming the state of the workpiece and the grindingwheel. In particular, relationships between working efficiency etc. andthe rotation center position of the workpiece, the position of thegrinding wheel spindle, the height of the upper surface of the machine,the diameter of the grinding wheel, the material of the wheel, thedimensions and shape of the opening portion of the cover, the dimensionsand shape of the open/close door formed on the cover and the like arenot sufficiently considered. Therefore, in the conventional grindingmachine, the loading/unloading of the workpiece, the replacement of thegrinding wheel or the maintenance and inspection of mechanisms arrangedtherein are conducted by opening a door formed on the side surface ofthe whole cover, and the loading/unloading of the workpiece or thereplacement of the workpiece is needed to conduct by using a workpieceloading/unloading device through a workpiece loading/unloading port.Thus, the working efficiency is low and, in particular, it is difficultfor a worker to load/unload of the workpiece or to replace the grindingwheel without using a working step.

Therefore, it is an object of the invention to provide a grindingmachine that allows easy maintenance and inspection thereof, enhancementinvisibility required when confirming the state of the workpiece and thegrinding wheel, easy loading/unloading of the workpiece and easyreplacement of the grinding wheel. In particular, the invention providesa grinding machine with a structure considered to allow the worker tonaturally take a posture based on ergonomic data.

Means For Solving The Problems

In order to achieve the object described above, the first inventionprovides a grinding machine comprising: a workpiece supporting/drivingdevice anteriorly mounted on a bed, and supporting a workpiece to berotatably driven; a grinding wheel head comprising a bearing portionsupporting a wheel spindle to be rotatably driven on which a grindingwheel is mounted, and a base mounted over the bed to be relativelymovable to the workpiece through a grinding wheel head slidingmechanism; a grinding wheel head feeder moving the grinding wheel headforward or backward to the workpiece supporting/driving device; acoolant supply unit supplying a coolant to a working area in which thegrinding wheel grinding processing the workpiece; a cover coveringinternal devices such as the workpiece supporting/driving device, thegrinding wheel head, the grinding wheel head feeder, the coolant supplyunit; and an open/close door formed on a part of an upper surface inworking space side of the cover, being capable of at leastloading/unloading of the workpiece and replacing the grinding wheel.

In the invention described above, the cover can comprise an upwardopen/close door or a sliding open/close door at least a part of theupper surface.

Further, in the invention described above, the open/close door can beformed on the upward open/close door or the sliding open/close door.

Further, in the invention described above, the open/close door cancomprise large size enough for a part of the workpiece to be visible inthe workpiece supporting direction, and the open/close door can compriselarge size as a length in a sliding direction of the grinding wheel headenough for a part of the grinding wheel to be visible from theopen/close door in the sliding direction of the grinding wheel head atthe stop of the grinding work.

Further, in the invention described above, the open/close door cancomprise the size larger than the maximum length of the workpiece in theworkpiece supporting direction and larger than the maximum diameter ofthe grinding wheel head in the sliding direction.

Further, in the invention described above, the workpiece can comprise arotation center position at not less than 200 mm and not more than 400mm from the front face of machine, and comprise a rotation centerposition at not less than 850 mm and not more than 1000 mm from thefloor face.

Further, in the invention described above, the wheel spindle cancomprise a center position thereof at not less than 250 mm and not morethan 500 mm from the front face of machine, and at not less than 850 mmand not more than 1000 mm from the floor face.

Further, in the invention described above, the grinding machine cancomprise a height of not less than 900 mm and not more than 1100 mm fromthe floor face.

Further, in the invention described above, the grinding wheel cancomprise an outer diameter of not less than 100 mm and not more than 200mm, and comprise CBN grinding wheel having aluminum or titanium disk asa core.

Further, in the invention described above, the open/close door can beformed within a region of not less than 200 mm and not more than 700 mmfrom the front face of machine, and not less than 1000 mm and not morethan 1200 mm from a floor face.

Furthermore, in the invention described above, the open/close door canbe formed on a region in which the workpiece or the grinding wheel headis replaceable in an open condition.

In order to achieve the object described above, the second inventionprovides a grinding machine comprising: a workpiece supporting/drivingdevice anteriorly mounted on a bed, and supporting a workpiece to berotatably driven; a grinding wheel head comprising a bearing portionsupporting a wheel spindle to be rotatably driven on which a grindingwheel is mounted, and a base mounted over the bed to be relativelymovable to the workpiece through a grinding wheel head slidingmechanism; a grinding wheel head feeder moving the grinding wheel headforward or backward to the workpiece supporting/driving device; acoolant supply unit supplying a coolant to a working area in which thegrinding wheel grinding processing the workpiece; and a cover coveringinternal devices such as the workpiece supporting/driving device, thegrinding wheel head, the grinding wheel head feeder, the coolant supplyunit, and formed below a height of an arm turning portion just proximalto a handling portion of a working robot performing a lift up/downoperation, so that a loading/unloading the internal portion of theworkpiece and a replacement of the grinding wheel can be conducted froma working space in a front face, centering around the lift up/downoperation.

Furthermore, in the invention described above, the cover can comprise anopen/close door within a region in which the lift up/down operation canbe performed.

Furthermore, in the invention described above, the loading/unloading ofthe workpiece, the replacement of the grinding wheel, and the liftup/down operation can be conducted by the robot.

Furthermore, in the invention described above, the cover can be formedbelow the height of the turning portion of the robot.

In order to achieve the object described above, the third inventionprovides a grinding machine comprising: a workpiece supporting portionsupporting a workpiece to be processed on a first rotating shaft; agrinding wheel supporting portion supporting a grinding wheel to processthe workpiece on a second rotating shaft; a side cover enclosing theworkpiece supporting portion and the grinding wheel supporting portionfrom the side; a upper cover enclosing a first opening portion formed onthe upper side by the side cover; and an open/close member formed on aworking space side of the upper cover, to open/close a second openingportion for a loading/unloading of the workpiece, and a replacement ofthe grinding wheel; and the second opening portion is formed on theupper cover, so that a straight line perpendicular to the first andsecond turning shafts in a center position thereof comprises a certaininclined angle to a floor face.

Furthermore, in the invention described above, the second openingportion can be formed on the upper cover, so as to comprise an inclinedangle of 45 degrees to 75 degrees as the certain inclined angle.

Advantages of the Invention

According to the invention, the opening portion is formed on the coverso that the loading/unloading of the workpiece and the replacement ofthe grinding wheel can be performed through at least an upper or frontsurface of the machine to facilitate the grinding work etc. This canenhance easy maintenance and inspection of the mechanisms arrangedtherein, visibility required when confirming the state of the workpieceand the grinding wheel, easy loading/unloading of the workpiece and easyreplacement of the grinding wheel. Generally, it is usual that workersare each working in different postures even if they have knowledge aboutthe ergonomic data. However, in the invention, since the opening portionof the cover is formed at a position determined by considering theergonomic data, the workers can work naturally in posture based on theergonomic data.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side view showing a cylindrical grinding machine in a firstpreferred embodiment according to the invention,

FIG. 2 is a plan view showing the cylindrical grinding machine shown inFIG. 1 as an overhead view when an upper open/close cover is dismounted,

FIG. 3 is a plan view showing the grinding machine shown in FIG. 1 as anoverhead view,

FIGS. 4A to 4E are schematic views showing the position and dimensionsof each part in the first preferred embodiment,

FIG. 5 is a side view showing a cylindrical grinding machine in a secondpreferred embodiment according to the invention,

FIG. 6A is a schematic view showing a cylindrical grinding machine in athird preferred embodiment when an upper open/close door is closed,

FIG. 6B is a schematic view showing a cylindrical grinding machine inthe third preferred embodiment when the upper open/close door is opened,

FIG. 7A is a schematic view showing a cylindrical grinding machine in afourth preferred embodiment when an open/close door of sliding type isclosed,

FIG. 7B is a schematic view showing a cylindrical grinding machine inthe fourth preferred embodiment when the open/close door of sliding typeis opened,

FIG. 8 is a side view showing a fifth preferred embodiment,

FIG. 9 is an explanatory view showing how an operating force of armchanges dependent on the directions, and

FIG. 10 is an explanatory view showing a front horizontal plane area tofacilitate a working which is conducted near a height of body section.

EXPLANATION OF REFERENCE NUMERALS

-   10 cylindrical grinding machine-   11 grinding machine body-   12 bed-   13 coolant chute-   24, 26 left and right work head-   27, 32 linear motor-   30 grinding wheel head-   33 slide-   31, 35 linear guide-   37 bearing portion-   45 side enclosing cover-   47 coolant supply nozzle-   50 attachment device-   51 coolant supply unit-   52 open port-   53 upper open/close cover-   53 s slide open/close cover-   54 bracket-   55 hinge-   57, 57 u, 57 s open/close door-   570 hinge-   58 slide rail-   59 gas cylinder-   61 working area-   62 sliding area-   63 frame body-   64 a, 64 b left and right accordion cover-   65 passing hole accordion cover-   66 separating cover-   69 lever mechanism-   73 rodless cylinder-   100 handling robot-   101 robot body-   102 first arm turning portion-   103 first arm-   104 second arm turning portion-   105 second arm-   106 handling portion-   G grinding wheel-   Wh grinding wheel disk-   W workpiece-   B floor face-   P worker

BEST MODE FOR CARRYING OUT THE INVENTION First Embodiment

A grinding machine in a first preferred embodiment according to theinvention will be explained below referring to the attached drawings.

FIG. 1 is a side view showing a cylindrical grinding machine in thefirst preferred embodiment, and FIG. 2 is a plan view showing thecylindrical grinding machine shown in FIG. 1 as an overhead view when anupper open/close cover is dismounted. The cylindrical grinding machine10 comprises a grinding machine body 11 and an attachment device 50. Inthe FIGS. 1, 2 the attachment device 50 comprises a coolant supply unit51, a mist collector 60, and a duct device 70 connecting the devices 51,60 to the grinding machine body 11. The grinding machine body 11comprises a bed 12, and the bed 12 mounts a workpiece supporting drivingdevice 20 on an upper surface of the front portion in left side of FIG.1 and a grinding wheel head 30 on an upper surface of the rear portionin right side of FIG. 1. The workpiece supporting driving device 20comprises a left work head 24 and a right work head 26 which arerespectively mounted and fixed on side surfaces of supports 22 mounteduprightly from the a work table 21 fixed on the bed 12, so as to beposition-adjustable in up/down direction in FIG. 2 along with a pair ofliner guides 25. A workpiece is supported between centers of the leftand right work heads 24, 26 rotatably around a horizontal axis line, andthe workpiece can rotate by a spindle motor (not shown) at a workpiecerotation center position departing from a front surface of the machineand a floor surface by a certain distance.

On the other hand, a pair of linear guides 31 extending in a Z-axisdirection parallel to a horizontal axis line of the workpiece is fixedon an upper surface of a rear portion of the bed 12. The linear guide 31guides a slide 33, and the slide 33 is moved by a Z-axis linear motor32. A pair of linear guides 35 extending in a X-axis directionperpendicular to the Z-axis is fixed on an upper surface of the slide33, and a base 34 of the grinding wheel head 30 is guided and supportedon the linear guides 35 so as to move forward or backward to theworkpiece W by a X-axis linear motor 27. The linear guides 31, 35, theslide 33, and the linear motors 27, 32 constitute a slide mechanism ofthe grinding wheel head 30 and a grinding wheel head feeder.

A bearing portion 37 is mounted on a front portion of the grinding wheelhead 30, and a grinding wheel shaft 38 of the grinding wheel G having adisk as a core is supported on the bearing portion 37 rotatably at acertain position from the front surface of the machine and the floorsurface B. A pulley 39 fixed to the grinding wheel shaft 38 is connectedto a pulley 41 fixed to an output shaft of a driving motor 40 through abelt 42 to rotate simultaneously, so that rotation power of the drivingmotor 40 can be transmitted to the grinding wheel shaft 38 and thegrinding wheel G. A coolant supply nozzle 47 is mounted on the bearingportion 37, so as to discharge the coolant supplied from a pipe line 47a installed in the grinding wheel head 30 toward a neighborhood ofgrinding point which is a contact point of the workpiece W and thegrinding wheel G.

Further, the grinding machine body 11 comprises the side enclosing cover45 covering and enclosing the workpiece supporting driving device 20 andthe grinding wheel head 30 disposed on the bed 12, and a circumferenceof the slide mechanism. The side enclosing cover 45 is bent inside inthe lower end portion thereof, and is fixed to a circumferential edge ofthe bed 12 by bolting. Further, the side enclosing cover 45 is formed tobe higher than the workpiece supporting driving device 20 and thegrinding wheel head 30, so as to enclose the side portions of theworkpiece supporting driving device 20 and the grinding wheel head 30.

Furthermore, the inside of the side enclosing cover 45 is separated intoa working area 61 where the workpiece supporting driving device 20, thegrinding wheel G, and the bearing portion 37 of the grinding wheel head30 are located, and a sliding area 62 where the base 34 of the grindingwheel head 30, the driving motor 40, the linear guides 31, 35, and theslide 33 etc. are located, and in an anteroposterior direction by aseparating cover 66. That is, a frame body 63 of rectangular shapecomprising a passing hole through which the bearing portion 37 passesfor entering from the sliding area 62 to the working area 61 is fixed toa front portion of the slide 33 through a supporting pole. Upper andlower outer ends of the frame body 63 are disposed near to a lowersurface of an upper open/close cover 53 described below and an uppersurface of the bed 12, and left and right outer ends thereof aredisposed as space is formed between left and right inner surfaces of theside enclosing cover 45, so as to allow the slide 33 to move in theZ-axis direction. The space formed at an outside of the left and rightouter ends of the frame body 63 is fixed to the left and right outerends of the frame body 63 at one end thereof, and the other end isobscured by left and right accordion covers 64 a, 64 b fixed to the leftand right inner surfaces of the side enclosing cover 45. An interspacebetween an inner circumference of the passing hole of the bearingportion 37 formed in the frame body 63 by cutting and an outercircumference of the bearing portion 37 is fixed to the bearing portion37 at one end thereof, and the other end is obscured by a passing holeaccordion cover 65 fixed to an end portion of the passing hole of theframe body 63. By the left and right accordion covers 64 a, 64 b and thepassing hole accordion cover 65, the separating cover 66 is formed, thecover 66 separating the inside of the side enclosing cover 45 into theworking area 61 and the sliding area 62.

FIG. 3 is a plan view showing the grinding machine shown in FIG. 1 as anoverhead view. An open port 52 to be an open portion capable ofoverlooking almost all of the working area 61 and the sliding area 62 isformed on an upper portion of the side enclosing cover 45, and the upperopen/close cover 53 is disposed on the open port 52.

As shown in FIG. 3, the upper open/close cover 53 is formed to the sizeof covering the whole of the open port 52 and in the form of plates. Abracket 54 is mounted parallel to the linear guide 31, on an upper endof the side enclosing cover 45 formed uprightly at the rear portion ofthe sliding area 62, and by a pair of hinges 55 mounted on the bracket54, the upper open/close cover 53 is pivoted on the upper end of theside enclosing cover 45 in a rear position of the machine so as to beopenable and closable by a turning mechanism.

Further, a pair of gas cylinders 59 to assist an open/close operation isinstalled in both sides of the bracket 54 and the upper open/close cover53. The gas cylinder 59 is installed in the upper open/close cover 53 atthe rear portion thereof, and piston rods projecting from the top ofcylinder are connected to the bracket 54, so as to assist the open/closeoperation to an open position A shown in FIG. 1 of the upper open/closecover 53. Furthermore, gas is encapsulated into the inside of gascylinders 59, so as to bias the upper open/close cover 53 in anextending direction of the cylinder shaft, that is, in an openingdirection of the upper open/close cover 53 by the effect of the gas.

Further, a lever mechanism 69 is installed in a front portion of theupper open/close cover 53, so as to be latched together with the sideenclosing cover 45 and to prevent the upper open/close cover 53 fromopening. When the lever mechanism 69 is released, the upper open/closecover 53 opens to the open position A by an effect of the cylinder, andif the upper open/close cover 53 is desired to be closed, a worker Pmoves the upper open/close cover 53 in a shrinking direction of the gascylinder 59, so that the upper open/close cover 53 is latched togetherat the close position by the effect of the lever mechanism 69.

Then, the upper open/close cover 53 contacts the circumference edge ofside enclosing cover 45, so as to be separated from the outside ofmachine, and approaches the separation cover 66, so as to separate theside enclosing cover 45 into the working area 61 and the sliding area62.

Therefore, if the upper open/close cover 53 is closed, the coolant isprevented from scattering outside from the working area 61, and thecoolant and the grinding dust are prevented from scattering from theworking area 61 to the sliding area 62.

On the other hand, a workpiece taking out port 56 as an opening portionis formed in a site of the upper open/close cover 53 corresponding tothe workpiece W, so as to take out the workpiece W when the upperopen/close cover 53 is closed, and an open/close door 57 is installed inthe workpiece taking out port 56, the door 57 being slidable in ananteroposterior direction so as to form an opening portion. Therefore,the taking out of workpiece W or the replacement of grinding wheel canbe performed from the opening portion in an open condition of theopen/close door 57.

The open/close door 57 comprises a window portion 57 a formed ofreinforced plastic, and a window frame 57 b in which the window portion57 a is inserted, the frame 57 b supported by slide rails 58 mounted onthe upper open/close cover 53 at the both end portions thereof. Further,a rodless cylinder 73 to automatically open/close the open/close door 57is mounted beside one of the slide rails 58.

Further, it is preferable that the length of open/close door 57 in theworkpiece supporting direction is large enough for a part of theworkpiece to be visible, and the length of open/close door 57 in thesliding direction of the grinding wheel head 30 is large enough for apart of the grinding wheel G to be visible from the open/close door 57at the stop of the grinding work. At the grinding work, the workpiece Wand the grinding wheel G contact each other, but at the stop of thegrinding work, the workpiece W and the grinding wheel G depart from eachother, therefore it is necessary to be visible from the open/close door57 in order to confirm the state of the grinding wheel G and performinspections etc. at the stop of the grinding work.

Further, it is preferable that the length of open/close door 57 in theworkpiece supporting direction is larger than the maximum length of theworkpiece W, and the length of open/close door 57 in the slidingdirection of the grinding wheel head 30 is larger than the maximumdiameter of the workpiece W. As described above, the function ofopen/close door 57 is to confirm the state of the grinding wheel G andperform inspection, but it is intended that the loading/unloading of theworkpiece W can be also performed from the opening portion of theopen/close door 57. Because the replacement of grinding wheel G isconducted at an appropriate time according to the working frequency, butthe replacement of workpiece W must be conducted at every working time,and if this is accompanied by the open/close operation of the upperopen/close cover 53 or the slide open/close cover 53 s, a drasticdecrease in the working efficiency or production efficiency is caused.

Again, referring to FIG. 1, a coolant chute 13 is installed in a part ofthe bed 12 forming a lower portion of the working area 61, so as toreceive the coolant discharged from the coolant supply nozzle 47 to thegrinding point. An exhaust conduit 71 of a duct device 70 is insertedinto the bed 12 from an opening portion of the rear surface.

The outer surface of exhaust conduit 71 is closed over the entirelength, so as to form a fluid passage of rectangular cross-sectionalshape capable of substantially keeping an air sealing, and thecross-sectional shape comprises a sectional area large enough for thecoolant to flow at the lower portion of the rectangular cross-sectionalshape, and simultaneously for a certain volume of mist to pass at theupper portion. Further, the exhaust conduit 71 extends immediately belowthe working area 61, and the upper surface of top portion is opened, soas to enclose the outer circumference of lower end portion of thecoolant chute 13 in an airtight condition, and to receive the fluid froman opening of lower end of the coolant chute 13. A mist recovery conduit72 branches from an opening of upper surface just before the rear endportion of the exhaust conduit 71, and extends upward, so as to beconnected to an inhalation port 60 a of a mist collector 60 mounted on amounting board 74. The mist collector 60 is publicly known, and operatesto inhale the mist from the inhalation port 60 a by a vacuum effect andto separate the mist into air components and liquid components, forexample, by centrifugal separation, so as to exhaust the air componentsto air and to reflux the liquid components to a coolant storage tank 52of the coolant supply unit 51.

The coolant supply unit 51 operates to store the coolant in the tank 52,to pump up the coolant in the tank 52 by a pump unit (not shown), tosend the coolant from a discharging pipe 67 to a pipe line 47 a througha flexible hose 68, and to supply the coolant from the coolant supplynozzle 47 mounted on the bearing portion 37 to a neighborhood of thegrinding point at which the grinding wheel G grinds the workpiece W.

Next, a grinding work in the first preferred embodiment, and along withthis, a loading/unloading of the workpiece and a replacement of thegrinding wheel will be explained.

The workpiece W is loaded after opened by an open/close operation of theupper open/close cover 53 or the slide open/close cover 53 s. Or, it isloaded from an opening portion after the open/close door 57 is opened.The worker P is located in a working space where the loading/unloadingof the workpiece and the replacement of the grinding wheel can beconducted.

When the workpiece W is loaded between the left and right work heads 24,26, left and right servomotors (not shown) are driven, the left andright work heads 24, 26 get closer to each other by a left and rightwork head moving device, the workpiece W is sandwiched between left andright centers 24 a, 26 a, the open/close door 57 is closed, and thegrinding work is started. Left and right work head servomotors arerotated synchronously, the workpiece W is driven to rotate from bothends. The slide 33 is moved in the Z axis direction by a Z axis linearmotor 32, so as to align the grinding wheel G with a working site in theZ axis direction. A X-axis linear motor 27 is driven, the grinding wheelhead 30 is carried forward at a fast feeding speed, a rough grindingfeeding speed, an accurate grinding feeding speed, the coolant issupplied from the coolant supply nozzle 47 to a working zone by thecoolant supply unit 51, and the working site of the workpiece W isground by the grinding wheel G driven to rotate by a driving motor 40through a belt 42.

The coolant supplied in the working zone lubricates and cools thegrinding point where the grinding wheel G grinds the workpiece W, anddrops into the coolant chute 13 opened just below the working zonetogether with the grinding dust, and is recovered in the coolant storagetank 51 a or the mist collector 60 through the exhaust conduit 71together with the mist produced simultaneously.

The frame body 63 of the separating cover 66 is moved in the Z axisdirection according to the movement of slide 33 in the Z axis direction,and the left and right accordion covers 64 a, 64 b fixed to left andright outer edges of the frame body 63 in one end thereof are elongatedand contracted, so as to obscure a space formed between outsides of theleft and right outer edges of the frame body 63 and left and right innersurfaces of the side enclosing cover 45. When the bearing portion 37 ofgrinding wheel head 30 moves forward or backward in the X axisdirection, a passing hole accordion cover 65 fixed to the outercircumference of the bearing portion 37 in one end thereof is elongatedand contracted, so as to obscure an interspace between the bearingportion 37 and the passing hole. Further, in the upper part, the upperopen/close cover 53 seals the grinding machine body 11 together with theside enclosing cover 45.

Therefore, the separating cover 66 comprising the left and rightaccordion covers 64 a, 64 b and the passing hole accordion cover 65, theupper open/close cover 37, and the side enclosing cover 45 separate theinside of the side enclosing cover 45 into the working area 61 where thegrinding wheel G grinds the workpiece W and the sliding area 62 wherethe grinding wheel head 30 is guided in the Z axis and X axis directionsby the linear guides 31, 35, so that a decrease in a guide accuracy andfeeding accuracy can be prevented, the decrease in the accuracies beingcaused by the penetration of grinding dust and coolant into the linearguides 31, 35 and the linear motor 27, 32.

When the grinding work of the workpiece W is completed, the grindingwheel head 30 is moved backward at a rapid feedrate, after thecompletion of backward movement of grinding wheel head 30 it is openedby the open operation of upper open/close cover 53, slide open/closecover 53 s or open/close door 57, the workpiece W is taken out to theoutside of machine, and then one grinding cycle is completed.

And, at the time of replacement of grinding wheel, the worker P operatesthe lever mechanism 69, so as to release the latched condition betweenthe upper open/close cover 53 and the side enclosing cover 45. The upperopen/close cover 53 is whirled to the opening position A by an effect ofthe gas cylinder 59, so that the upper open/close cover 53 is opened.When the upper open/close cover 53 is opened, the upper portions ofworking area 61 and sliding area 62 separated by the separating cover 66are opened.

By this, the worker P can replace the grinding wheel G installed in thebearing unit 37 from the upside of grinding wheel head 30. Further, atthe replacement of grinding wheel all of the devices in the sideenclosing cover 45 are visible, so that for example, states of the belt42, the linear guides 31, 35 etc. can be confirmed.

“Design Learning of Machine Tool (Basic Edition)” edited by JapanMachine Tool Builders' association (p. 64 to p. 66), describes below.That is, “Usability in view of ergonomics generally is determined byfactors such as (1) compatibility of size, (2) operability, (3)information display characteristic, (4) safety, (5) environmentaladaptability, (6) design characteristic, (7) functionality. Thecompatibility of size means for example, a matching between a grip sizeof lever and a size of human hand or machine tool. The operability meansa matching between human motility characteristic or muscle strength andan operation characteristic of the product itself. The informationdisplay characteristic means for example, a relationship between size,brightness etc. of character, figure etc. shown in display screen of NCunit and human visual feature. The safety means existence ornonexistence of factors causing harm to operators at the operation, andthe environmental adaptability means existence or nonexistence ofadverse effects on human beings by ambient noise, vibration, inadequateillumination, working liquid etc. The design characteristic, which isdependent on cultures of the period and the region, means whether theformative sense is preferred by workers. The functionality means whetherit can functionally provide an adequate satisfaction, based on thefactors described above. To satisfy the factors is very important formaximizing mental and physical ability of human beings having alimitation of “fatigue”. Further, the fatigue decreases concentrationpower of workers, also becomes a source of accidents, and finallydecreases the productivity of machine tool. It is generally difficult tosatisfy all of the factors, so that consideration that priorities areset to each product is conducted. Recently, the safety, theenvironmental adaptability and the design characteristic have also beenemphasized.”

FIG. 9 is disclosed in the literature described above, and shows anevaluation result of an upright position working point in view of muscleactivity and energy metabolism. By this, it is recognized that thevicinity of elbow height is preferable as an operation position, and nokeeping from body position not less than 300 mm is also preferable.

FIG. 10 is disclosed in the literature described above, and shows afront horizontal plane area to facilitate a working which is conductednear a height of body section. In case of M5PC (M5PC means a man havingthe 5^(th)-lowest body height out of 100 men, and similarly, W5PC meansa woman having the 5^(th)-lowest body height out of 100 women, M95PCmeans a man having the 95^(th)-lowest body height out of 100 men), it isrecognized that the front side within 450 mm is a distance for acomfortable operation. Further, it shows that a distance for easy reachof hands changes along with a line inclined at angle of about 60 degreesto a floor face.

In FIG. 9 and FIG. 10, the body heights of workers are based on thedistribution shown in FIG. 2.7.1 in the literature described above.

When a position size of each part is ergonomically investigated based onthe data described above, the results are shown below.

FIGS. 4A to 4E is a schematic view showing the position and dimensionsof each part in the first preferred embodiment.

According to FIG. 9, if more than 1200 mm, a preferable result of theupright position working point in view of muscle activity and energymetabolism cannot be obtained. Therefore, in the first preferredembodiment, as shown in FIG. 4A, it is preferable that the height ofmachine upper face (Hh) is not more than 1200 mm from the floor face B.

Further, according to FIG. 10, if the workers P have body heights withinthe range of 90% eliminated each 5% in the upper and lower limits, whenthe workers P replace the workpiece W and the grinding wheel G, in acase that the height of machine upper face is 1000 mm, it is preferablethat the opening portion is located within the range of 400 mm to 800 mmfrom the machine front face, and in a case that the height of machineupper face is 1200 mm, it is preferable that the opening portion islocated within the range of 300 mm to 650 mm from the machine frontface. Therefore, as shown in FIG. 4B, it is preferable that the positionLk of the opening portion from the machine front face is not less than600 mm.

Similarly, based on the ergonomic data in FIG. 10, as shown in FIG. 4C,it is preferable that the rotation center position of the workpiece W iswithin a range of LW1 to LW2, and LW1 and LW2 are 200 mm and 400 mmrespectively. Further, it is preferable that the position is within arange of H1 to H2 from the floor face B, and H1 and H2 are 850 mm and1000 mm respectively.

Further, as shown in FIG. 4D, it is preferable that the rotation centerposition of the grinding wheel shaft 38 is within a range of LG1 to LG2,and LG1 and LG2 are 250 mm and 500 mm respectively. Further, it ispreferable that the position is within a range of H3 to H4 from thefloor face B, and H3 and H4 are 850 mm and 1000 mm respectively.

For the reason described above, in a case that the loading/unloading ofthe workpiece and the replacement of the grinding wheel are conducted,for example, from the opening portion of open/close door 57 shown inFIG. 3, it is preferable that the opening portion is formed within arange obtained by a calculation that based on the ergonomic data in FIG.10, from numerical values of 300 mm to 800 mm from the machine frontface, and 1000 mm to 1200 from the floor face, in consideration ofworkability of the workers of the M5PC and W5PC sides, adjusted valuesof 100 mm are reduced, that is, the range is 200 mm to 700 mm from themachine front face, and 900 mm to 1100 mm from the floor face.

Further, the rotation center position of the workpiece W is disposedwithin a range of 200 mm to 400 mm, and 850 mm to 1000 mm from the floorface B, and also the rotation center position of the grinding wheelshaft 38 is disposed within a range of 250 mm to 500 mm, and 850 mm and1000 mm from the floor face B, so that the ergonomic data describedabove can be satisfied.

Simultaneously, it is preferable that the straight line extending fromthe center position of opening portion of open/close door 57 to therotation axis of the workpiece W and the rotation axis of the grindingwheel shaft 38 perpendicularly is almost along with the line of about 60degrees previously shown in FIG. 10, for example, lines within a rangeof 45 degrees to 75 degrees. Further, the center position of the openingportion of the open/close door 57 means an intersection of two diagonallines of a rectangular opening portion of the open/close door 57 shownin FIG. 3.

FIG. 4E shows the lines l₁ and l₂. Further, the upper open/close cover53 comprises the workpiece taking out port 56 formed as an openingportion, and the open/close door 57 is formed on the opening portion. Itis preferable that the inclined angles O₁, O₂ of the lines l₁ and l₂perpendicular to the center position C of the opening portion, therotation axis O of the workpiece W and the rotation axis O₂ of thegrinding wheel shaft 38 to the line H parallel to the floor face arewithin a range of 45 degrees to 75 degrees.

Further, it is preferable that the grinding wheel comprises CBN (CubicBoron Nitride) grinding wheel, a disk for grinding wheel Wh comprisesaluminum, titanium or those alloys, and the outer diameter of thegrinding wheel G is not less than 100 mm and not more than 200 mm.

According to the first preferred embodiment described above, the easymaintenance and inspections of mechanisms arranged therein, an increasein visibility when the states of a workpiece and a grinding wheel areconfirmed, and the easy loading/unloading of the workpiece and the easyreplacement of the grinding wheel can be enhanced.

Further, the machine (grinding machine) comprising the height of themachine upper surface, the rotation center position of the workpiece W,and the position of the grinding wheel shaft 38, as shown by dottedlines in FIG. 4A and FIG. 4B, enables the workers P to load/unload theworkpiece and replace the grinding wheel mainly by arm operation withoutmotions putting stress on their waists such as stretch motion, bowmotion, so that the working efficiency and the productivity can beenhanced, and also the safety of the workers can be enhanced. Further,the grinding wheel comprising CBN can be formed to be smaller in theouter diameter, and the disk Wh comprising aluminum, titanium or thosealloys can be formed to be lighter in the weight, and also by this theworking efficiency, the productivity, and also the safety of the workerscan be enhanced.

Further, in the first preferred embodiment a structure that the hinge 55is mounted in the rear position of side enclosing cover 45 so as toallow the upper open/close cover 53 to be openable and closable from thefront portion to the rear portion has been explained, but the inventionis not limited to such a structure, the other structure that the hinge55 is mounted in the upper position on the side of side enclosing cover45 so as to allow the upper open/close cover 53 to be openable andclosable in the side portion of the grinding machine body 11 can beadopted. Furthermore, the mounting method is also not limited to amethod using the hinge 55, but any mechanism that can swivel the upperopen/close cover 53 can be adopted.

Second Embodiment

FIG. 5 is a side view showing a cylindrical grinding machine in a secondpreferred embodiment according to the invention.

The cylindrical grinding machine 10 comprises a slide open/close cover53 s to slide from the front portion to the rear portion based on ahorizontal slide mechanism being public known, instead of swiveling theupper open/close cover 53.

In order to allow the slide open/close cover 53 s to slide from thefront portion to the rear portion, it is necessary that the height ofattachment device 50 is installed lower than the sliding height of slideopen/close cover 53 s, so as to prevent the attachment device 50installed in the rear portion of grinding machine body 11 frominterfering.

Also in the second preferred embodiment, similarly to the firstpreferred embodiment, it is preferable that the values of the height ofmachine upper face (Hh), the rotation center position of the workpiece W(LW1, LW2, H1, H2), and the rotation center position of the grindingwheel shaft 38 (LG1, LG2, H3, H4) are similar to the values described inthe first preferred embodiment.

Further, it is preferable that the grinding wheel comprises CBN (CubicBoron Nitride) grinding wheel, a disk for grinding wheel Wh comprisesaluminum, titanium or those alloys, and the outer diameter of thegrinding wheel G is not less than 100 mm and not more than 200 mm.

According to the second preferred embodiment described above, similarlyto the first preferred embodiment, the easy maintenance and inspectionsof mechanisms arranged therein, an increase in visibility when thestates of the workpiece W and the grinding wheel G are confirmed, andthe easy loading/unloading of the workpiece and the easy replacement ofthe grinding wheel can be enhanced. Further, the slide open/close cover53 s does not need an open/close space in the upper direction, and doesnot need a power against gravity at the open/close operation, so thatthe open/close operation can be realized by a simple slide mechanism,and can be easily performed by the workers P.

Third Embodiment

FIG. 6A is a schematic view showing a cylindrical grinding machine in athird preferred embodiment when an upper open/close door 57 u is closed,and FIG. 6B is a schematic view showing a cylindrical grinding machinein the third preferred embodiment when the upper open/close door 57 u isopened.

As shown in FIG. 6A, the cylindrical grinding machine 11 comprises anopen/close door 57 u as an opening portion in the upper open/close cover53, by which the upper surface and/or the front surface of the machinecan be opened/closed with a central focus on the hinge 570. As shown inFIG. 6B, the open/close door 57 u is opened by the workers P with acentral focus on the hinge 570 by hand, so that the workers P cancontact the grinding wheel G and the workpiece W. In this case, it ispreferable that the height (H_(L)) of the lower end of opening portionof machine front surface is not less than 1000 mm from the bottomsurface.

Also, it is preferable that the values of the height of machine upperface (Hh), the rotation center position of the workpiece W (LW1, LW2,H1, H2), and the rotation center position of the grinding wheel shaft 38(LG1, LG2, H3, H4) are similar to the values described in the firstpreferred embodiment.

Further, it is preferable that the grinding wheel comprises CBN (CubicBoron Nitride) grinding wheel, a disk for grinding wheel Wh comprisesaluminum, titanium or those alloys, and the outer diameter of thegrinding wheel G is not less than 100 mm and not more than 200 mm.

According to the third preferred embodiment described above, as shown inFIG. 6B, with just the opening operation in the upper direction ofopen/close door 57 u by the workers P, the easy loading/unloading of theworkpiece W and the easy replacement of the grinding wheel and theincrease in visibility when the states of the workpiece W and thegrinding wheel G are confirmed can be enhanced. Further, as shown inFIGS. 6A, 6B, the workers can load/unload the workpiece and replace thegrinding wheel mainly by arm operation without motions putting stress ontheir waists such as stretch motion, bow motion.

Fourth Embodiment

FIG. 7A is a schematic view showing a cylindrical grinding machine in afourth preferred embodiment when an open/close door of sliding type isclosed, and FIG. 7B is a schematic view showing a cylindrical grindingmachine in the fourth preferred embodiment when the open/close door ofsliding type is opened.

As shown in FIG. 7A, the cylindrical grinding machine 10 comprises anopen/close door 57 s to slide from the front portion to the rear portionon the machine upper surface so as to be openable and closable as anopening portion in the upper open/close cover 53. The open/close door 57s slides on the machine upper surface by hand of the workers P or anopen/close mechanism (not shown), so that as shown in FIG. 7B theworkers P can contact the grinding wheel G and the workpiece W. Further,also in the fourth preferred embodiment, it is preferable that theheight (H_(L)) is not less than 1000 mm from the bottom surface.

According to the fourth preferred embodiment described above, inaddition to the preferable advantages of the first preferred embodiment,as shown in FIG. 7B, with just the opening operation due to the slidingof open/close door 57 s by the workers P, the easy loading/unloading ofthe workpiece W and the easy replacement of the grinding wheel and theincrease in visibility when the states of the workpiece W and a grindingwheel G are confirmed can be enhanced. In this case, the workers P canconduct the opening operation more easily due to the sliding ofopen/close door 57 s than the structure shown in FIG. 6A, and can alsokeep the open/close door 57 s as it is.

Fifth Embodiment

FIG. 8 is a side view showing a fifth preferred embodiment. In the fifthpreferred embodiment, a handling robot conducts the loading/unloading ofthe workpiece W and the replacement of the grinding wheel G.

The handling robot 100 comprises a robot body 101, a first arm 103mounted on the robot body 101 through a first arm turning portion 102being rotatable, a second arm 105 mounted through a second arm turningportion 104 being rotatable, and a handling portion 106 mounted on theend portion of second arm 105 apart from the robot body 101, the portion106 being rotatable and capable of grasping. Further, the handling robot100 comprises a control means and actuators at each part (not shown)based on public known technical means, so that for example, the handlingrobot 100 performs works, such as the loading/unloading of the workpieceW and the replacement of the grinding wheel G based on a remote controlby an operator.

In the works of the loading/unloading of the workpiece W and thereplacement of the grinding wheel G, first, the handling robot 100 ismoved to such a position that the robot body 101 does not contact themachine front surface. Next, the first arm 103 and the second arm 105are operated to allow the handling portion 106 to approach, and grasp orrelease the objective workpiece W or grinding wheel G, so that theworkpiece W can be carried in/out or the grinding wheel G can bereplaced.

Further, it is preferable that the height of the upper open/close cover53, the slide open/close cover 53 s, or the machine upper surface or thelower end of the opening portion is not higher than such a height thatthe loading/unloading of the workpiece W and the replacement of thegrinding wheel G can be conducted from a working space, centering aroundthe lift up/down operation. Alternatively, it is preferable that theheight of the upper open/close cover 53, the slide open/close cover 53s, or the machine upper surface or the lower end of the opening portionis not higher than a height of the arm turning portion nearest to thehandling portion 106 of the handling robot 100.

Since two arms are used in the preferred embodiment, so that the nearestarm turning portion corresponds to the second arm turning portion 104.Further, the handling robot 100 can be replaced with the workers P.

According to the structure described above, even if theloading/unloading of the workpiece W and the replacement of the grindingwheel G are conducted by the handling portion 106, the arm portion andthe handling portion never contact the machine or the cover at theoperation of the handling robot 100. Further, the loading/unloading ofthe workpiece W and the replacement of the grinding wheel G can beconducted from a working space, centering around the lift up/downoperation, and also can be conducted mainly with a central focus on theoperation of arm portion, so that the handling robot is not required tomove up/down and can prevent vain consumption of energy.

The operation of the handling robot 100 described above is applicable tothe operation of the worker P of a human being. The first arm turningportion 102 of the handling robot 100 corresponds to a human shoulder,the first arm corresponds to an upper arm, the second arm turningportion 104 corresponds to an elbow, the second arm 105 corresponds to afront arm, and the handling portion 106 corresponds to a hand includinga wrist.

Therefore, if a human being or the handling robot equivalent to a humanbeing is set as the workers P, similarly to the first preferredembodiment, it is preferable that the values of the height of machineupper face (Hh), the rotation center position of the workpiece W (LW1,LW2, H1, H2), and the rotation center position of the grinding wheelshaft 38 (LG1, LG2, H3, H4) are similar to the values described in thefirst preferred embodiment.

Further, it is preferable that the grinding wheel comprises CBN (CubicBoron Nitride) grinding wheel, a disk for grinding wheel Wh comprisesaluminum, titanium or those alloys, and the outer diameter of thegrinding wheel G is not less than 100 mm and not more than 200 mm.

According to the fifth preferred embodiment, the easy loading/unloadingof the workpiece and the easy replacement of the grinding wheel can beenhanced. Further, if a human being or the handling robot comprising anobject recognition tool equivalent to a human being is set as theworkers P, similarly to the other preferred embodiments, the easymaintenance and inspections of mechanisms arranged therein, and anincrease in visibility when the states of the workpiece and the grindingwheel are confirmed can be enhanced, and the working efficiency, theproductivity and the safety of the workers can be also enhanced.

1. A grinding machine, comprising: a workpiece supporting/driving deviceanteriorly mounted on a bed, and supporting a workpiece to be rotatablydriven; a grinding wheel head comprising a bearing portion supporting awheel spindle to be rotatably driven on which a grinding wheel ismounted, and a base mounted over the bed to be relatively movable to theworkpiece through a grinding wheel head sliding mechanism; a grindingwheel head feeder moving the grinding wheel head forward or backward tothe workpiece supporting/driving device; a coolant supply unit supplyinga coolant to a working area in which the grinding wheel grindingprocessing the workpiece; a cover covering internal devices such as theworkpiece supporting/driving device, the grinding wheel head, thegrinding wheel head feeder, the coolant supply unit; and an open/closedoor formed on a part of an upper surface in working space side of thecover, being capable of at least loading/unloading of the workpiece andreplacing the grinding wheel.
 2. The grinding machine according to claim1, wherein: the cover comprises an upward open/close door or a slidingopen/close door at least a part of the upper surface.
 3. The grindingmachine according to claim 2, wherein: the open/close door is formed onthe upward open/close door or the sliding open/close door.
 4. Thegrinding machine according to claim 2, wherein: the open/close door isformed within a region of not less than 200 mm and not more than 700 mmfrom the front face of machine, and not less than 900 mm and not morethan 1100 mm from a floor face.
 5. The grinding machine according toclaim 1, wherein: the open/close door comprises large size enough for apart of the workpiece to be visible in the workpiece supportingdirection, and the open/close door comprises large size as a length in asliding direction of the grinding wheel head enough for a part of thegrinding wheel to be visible from the open/close door in the slidingdirection of the grinding wheel head at the stop of the grinding work.6. The grinding machine according to claim 1, wherein: the open/closedoor comprises the size larger than the maximum length of the workpiecein the workpiece supporting direction and larger than the maximumdiameter of the grinding wheel head in the sliding direction.
 7. Thegrinding machine according to claim 1, wherein: the workpiece comprisesa rotation center position at not less than 200 mm and not more than 400mm from the front face of machine, and comprises a rotation centerposition at not less than 850 mm and not more than 1000 mm from thefloor face.
 8. The grinding machine according to claim 1, wherein: thewheel spindle comprises a center position thereof at not less than 250mm and not more than 500 mm from the front face of machine, and at notless than 850 mm and not more than 1000 mm from the floor face.
 9. Thegrinding machine according to claim 7, wherein: the open/close door isformed on a region in which the workpiece or the grinding wheel head isreplaceable in an open condition.
 10. The grinding machine according toclaim 1, wherein: the grinding machine comprises a height of not lessthan 900 mm and not more than 1100 mm from the floor face.
 11. Thegrinding machine according to claim 1, wherein: the grinding wheelcomprises an outer diameter of not less than 100 mm and not more than200 mm, and comprises CBN grinding wheel having aluminum or titaniumdisk as a core.
 12. A grinding machine, comprising: a workpiecesupporting/driving device anteriorly mounted on a bed, and supporting aworkpiece to be rotatably driven; a grinding wheel head comprising abearing portion supporting a wheel spindle to be rotatably driven onwhich a grinding wheel is mounted, and a base mounted over the bed to berelatively movable to the workpiece through a grinding wheel headsliding mechanism; a grinding wheel head feeder moving the grindingwheel head forward or backward to the workpiece supporting/drivingdevice; a coolant supply unit supplying a coolant to a working area inwhich the grinding wheel grinding processing the workpiece; and a covercovering internal devices such as the workpiece supporting/drivingdevice, the grinding wheel head, the grinding wheel head feeder, thecoolant supply unit, and formed below a height of an arm turning portionjust proximal to a handling portion of a working robot performing a liftup/down operation, so that a loading/unloading the workpiece and areplacement of the grinding wheel can be conducted from a working spacein a front face, centering around the lift up/down operation in theinternal portion of the grinding machine.
 13. The grinding machineaccording to claim 12, wherein: the cover comprises an open/close doorwithin a region in which the lift up/down operation can be performed.14. The grinding machine according to claim 12, wherein: theloading/unloading of the workpiece, the replacement of the grindingwheel, and the lift up/down operation are conducted by the robot. 15.The grinding machine according to claim 14, wherein: the cover is formedbelow the height of the turning portion of the robot.
 16. A grindingmachine, comprising: a workpiece supporting portion supporting aworkpiece to be processed on a first rotating shaft; a grinding wheelsupporting portion supporting a grinding wheel to process the workpieceon a second rotating shaft; a side cover enclosing the workpiecesupporting portion and the grinding wheel supporting portion from theside; a upper cover enclosing a first opening portion formed on theupper side by the side cover; and an open/close member formed on aworking space side of the upper cover, to open/close a second openingportion for a loading/unloading of the workpiece, and a replacement ofthe grinding wheel; and the second opening portion is formed on theupper cover, so that a straight line perpendicular to the first andsecond turning shafts in a center position thereof comprises a certaininclined angle to a floor face.
 17. The grinding machine according toclaim 16, wherein: the second opening portion is formed on the uppercover, so as to comprise an inclined angle of 45 degrees to 75 degreesas the certain inclined angle.
 18. The grinding machine according toclaim 8, wherein: the open/close door is formed on a region in which theworkpiece or the grinding wheel head is replaceable in an opencondition.